Maxime BORDIVAL

Maxime Bordival's PhD Thesis - 6/7/2009

Abstract

Numerical modelling and optimisation of the infrared heating step for the stretch-blow-moulding or PET bottles

Maxime Bordival - 6 July 2009

During a stretch-blow-moulding cycle, the heat conditioning of the preform is a critical step. We propose an optimisation method allowing to automatically compute the best set of process parameters for the infrared oven.
Firstly, we couple the Nelder-Mead optimisation algorithm with finite-element simulations of the blowing step performed using ABAQUS®. The goal is to calculate the optimal temperature distribution inside the preform, in order to provide a bottle with a uniform thickness. Secondly, we couple a sequential quadratic programming method with an in-lab software devoted to the 3D simulation of the infrared heating. This method aims to calculate the best set of parameters for the infrared oven. Numerical results of the optimisation have been qualitatively validated by comparison with experimental measurements performed using a semi-industrial blowing machine and a simple-design bottle.
The radiative properties of PET are measured using an infrared spectrometer. These properties are used to calculate the spectral radiative absorption of PET. Heating simulations are validated with temperature measurements performed with an infrared camera. We also have developed a sensor in order to measure the thermal contact resistance between the polymer and the mould. In addition, the air flow rate was measured inside the preform, and applied as an input parameter. Then, the air pressure is automatically computed using a thermodynamic model. Experimental measurements, performed on an in-lab blowing machine, are used to validate the blowing kinematics and the thickness distribution of the bottle predicted by the simulations.

Key words:
Stretch-blow-moulding, Infrared heating modelling, Finite element simulations, Numerical optimization

Last modified: 08/04/2009 03:02 PM